Dimensional information of an indoor scene, such as a room and a hallway, can be useful for a wide variety of applications. During a building construction, dimensional information can be used to monitor the structure to ensure that it meets requirements of specifications and drawings. During building maintenance, dimensional information can determine whether the structure remains consistent with existing building codes, and to quantify any flaws, e.g., cracks. In addition, in the context of construction automation, dimensional information is useful for any robot performing tasks during the construction, such as installing windows.
For a window installing robot, the robot needs to know the actual size of the window frame as constructed, instead of the designed size due to tolerance discrepancies. With this dimensional information, the robot can install the window correctly and ensure that it fits into the frame accurately. Additionally, the dimensions of any openings are of high significance for an autonomous robot to move in indoor environments. For example, when passing through a door, the robot has to detect the dimension of the opening space so that it can automatically decide whether to directly go through this door or to use another way.
In the prior art, three-dimensional (3D) sensors that use a rotating laser have been commonly used for generating a 3D model of an indoor scene and measuring dimensions in the 3D model. Those sensors can generate 3D models with long-range and 360-degree coverage from a single location. However, those sensors are expensive and require a long scanning time, during which those sensors need to be placed at a fixed location.
Recently 3D sensors that have short-range and small field-of-view coverage have been readily available. Those sensors enable single-shot, real-time scanning. To generate large-scale 3D models using those sensors, one method registers multiple frames acquired by those sensors using simultaneous localization and mapping (SLAM) techniques. However, that method accumulates drift errors in the registration, leading to lower accuracy for dimensional measurements.
In terms of user interaction, one method provides a construction quality inspection and management system with user interaction to quickly access to data. Another method for an interactive simulation modelling provides step-by-step guidance for the user to build a simulation model. The user guidance acts as a tutor for the user. Given a reference image, yet another method provides guidance for the user to take an image from the same viewpoint where the reference image was taken.